CN1167184C - High-frequency oscillation circuit - Google Patents

Abstract

An object of the present invention is to provide a high-frequency oscillation circuit free from characteristics such as a reduction in S/N ratio due to external electromagnetic interference, in which bases of first and second oscillation transistors are connected together directly or via a capacitor having sufficiently low impedance at an oscillation frequency, and a differential signal output is obtained as an oscillation output from between emitters of the first and second oscillation transistors. It is another object of the present invention to provide a resonance circuit for an oscillation circuit and providing a high Q factor and a high frequency oscillation circuit using the same so that an oscillation circuit IC has a high S/N ratio.

Description

High frequency oscillation circuit

The present invention relates to high frequency oscillation circuits such as voltage controlled oscillators in radio communication equipment such as cellular phones or satellite communication equipment.

Conventional techniques are described with reference to the drawings.

Fig. 19 is a circuit diagram of a conventional high frequency oscillation circuit. In this figure, 1 and 17 are oscillation transistors; 2, 3, 4, 18, 19 and 20 are capacitors; 5 and 21 are resonator coupling capacitors; 6 and 22 are output coupling capacitors; 7 is a resonator; 8 and 23 is a varactor coupling capacitor; 9 and 24 are varactors; 11, 12, 13, 26, 27 and 28 are bias resistors; 14 and 29 are varactor bias choke coils (choke); 15 and 16 are high-frequency output terminals; 10, 25 and 30 are high-frequency choke coils; 31 and 32 are bypass capacitors; 33 is a tuning voltage power supply terminal; 34 is a bias power supply terminal.

A conventional high-frequency oscillation circuit of this structure operates as follows.

In FIG. 19 , the bases of oscillation transistors 1 and 17 are grounded via capacitors 4 and 20 having sufficiently low impedance in the oscillation frequency band, respectively. Capacitors 2 and 18 are connected to transistors 1 and 17 respectively as collector-emitter capacitive elements. In addition, the capacitors 3 and 19 are connected between the ground and the emitters of the transistors 1 and 17 respectively, which is also equivalent to being connected between the emitter and the base, because this circuit is of the grounded base type. Furthermore, the resonator 7 connected via the resonator coupling capacitors 5 and 21 is a half-length resonator whose tip is open. Since the midpoint of the resonator is equivalent to being used as a short-circuit point to ground, the resonator 7 is equivalent to being connected between the collector and the base of the transistor 1 via the resonator coupling capacitor 5 as an inductive element, and via the resonator coupling capacitor 5 as an inductive element. A capacitor 21 of the element is connected between the collector and the base of the transistor 17 .

Thus, in the circuit of FIG. 19, two grounded base oscillation oscillation circuits use a half-wave oscillator for oscillation operation to provide oscillation signals whose phases are shifted by 180° from each other through the output coupling capacitors 6 and 22 from high Their output is obtained between the frequency output terminals 15 and 16 as a differential signal output between the two circuits.

Furthermore, each of the varactors 9 and 24 is connected to the resonator 7 via varactor coupling capacitors 8 and 23, respectively. In addition, since the varactor bias choke coils 14 and 29 provide ground potential to the anodes of the varactor diodes 9 and 24 in a direct current manner, the voltage value applied to the tuning voltage power supply terminal 33 via the high frequency choke coil 30 changes. The capacitance values of varactor diodes 9 and 24 are increased to change the oscillation frequency.

In addition, the oscillating circuit for performing this circuit operation can be formed on the IC by IC technology, and the components include not only the oscillating transistors 1 and 17 and their peripheral components, but also the resonator 7 and the resonance circuit constituted by the varactor diodes 9 and 24 .

However, in the above structure, the capacitors 3, 4, 19, and 20 are grounded, so if external electromagnetic interference occurs, a potential difference may be generated on the ground surface of the circuit board on which the circuit is mounted, thereby losing balance between the two transistors and lowering S /N ratio.

In addition, since the resonator 7 and the varactor diodes 9 and 24 are formed using an IC process on an IC chip, it is not easy to fabricate an element with a high Q factor, ie, a small loss. As a result, the resonance circuit of such an oscillation circuit IC cannot easily realize a high Q factor, and thus it is difficult to provide a high C/N ratio to the oscillation circuit IC.

SUMMARY OF THE INVENTION In view of these problems, an object of the present invention is to provide a high frequency oscillating circuit which has no characteristics such as a drop in S/N ratio under external electromagnetic disturbance.

Another object of the present invention is to provide a resonant circuit capable of providing a high Q factor and a high frequency oscillating circuit using the resonant circuit to obtain a high S/N ratio for an oscillating circuit IC.

The present invention is a high-frequency oscillating circuit comprising first and second oscillating transistors, wherein the bases of the first and second transistors are connected together directly or via a capacitor whose impedance is lower than a predetermined value at the oscillating frequency, And the differential signal output obtained between the emitters of the first and second oscillating transistors is output as an oscillating output.

According to this structure, the capacitor connected between the base of the oscillating transistor and the ground is not connected to the ground pattern on the mounting circuit board, but the bases of the two oscillating transistors are connected directly or via the capacitor. Thus, a differential oscillation operation can be performed at a high frequency without using the ground pattern on the mounted circuit board, so it is possible to provide a high-frequency oscillation circuit which is free from the common occurrence in the ground pattern on the mounted circuit board. Noise sources, or no characteristics such as S/N ratio degradation even when external electromagnetic interference is generated.

In particular, if the two bases are directly connected, unwanted impedance loading of the base at the oscillation frequency is eliminated, thereby providing a high-frequency oscillation circuit free from characteristics such as a drop in the S/N ratio.

Furthermore, the present invention is a high-frequency oscillation circuit comprising first and second oscillation transistors, wherein collectors of the first and second transistors are connected together directly or via a capacitor whose impedance is lower than a predetermined value at the oscillation frequency, and A differential signal output obtained between the emitters of the first and second oscillation transistors is output as an oscillation output.

According to this structure, the capacitor connected between the collector of the oscillating transistor and the ground is not connected to the ground pattern on the mounting circuit board, but the collectors of the two oscillating transistors are connected directly or via the capacitor. Thus, a differential oscillation operation can be performed at a high frequency without using the ground pattern on the mounted circuit board, so it is possible to provide a high-frequency oscillation circuit that is not affected by the common mode generated in the ground pattern on the mounted circuit board. Influence of noise sources, or no characteristics such as S/N ratio drop even when external electromagnetic interference is generated.

In particular, if the two collectors are directly connected, an unwanted impedance load on the collector at the oscillation frequency is eliminated, thereby providing a high-frequency oscillation circuit free from characteristics such as a drop in the S/N ratio.

Furthermore, according to the present invention, the resonator, varactor diode, capacitor, and choke coil constituting the resonance circuit for the oscillation circuit IC are integrated as a module, separate from the negative resistance generating circuit constituting the IC and including the oscillation transistor.

Thus, a high Q factor is obtained by forming a strip conductor resonator on a dielectric substrate. Furthermore, instead of using an IC process, the varactor can include conventional single discrete components to increase the Q factor and capacitance ratio, thereby providing a resonant circuit with a high Q factor. Thus, combining this resonance circuit with the oscillation circuit IC can provide the oscillation circuit IC with a high S/N ratio.

It is obvious from the above description that the present invention connects the bases and emitters of two oscillating transistors or their collectors and emitters via capacitors instead of ground, regardless of external electromagnetic interference, characteristics such as S/N ratio, etc. won't drop.

The present invention is also advantageous in that a common collector current path is used for the oscillator transistor and the buffer amplifier transistor to reduce current consumption.

The invention also has the advantage that the Q factor and capacitance ratio can be increased, thereby providing a resonant circuit with a high Q factor. Thus, combining this resonance circuit with the oscillation circuit IC can provide an oscillation circuit with a high S/N ratio.

The advantage of the present invention is also that the base grounding capacitor is not connected between the two oscillating transistors, but the bases or collectors of the two oscillating transistors are directly connected, thereby providing a high-frequency oscillating circuit, the circuit Not affected by the impedance of the ground capacitor, or without characteristics such as S/N ratio drop.

Furthermore, according to the present invention, even if the buffer amplifier is connected to the oscillation circuit, no capacitor is connected between the emitters of the two buffer amplifier transistors, but the emitters of the two buffer amplifier transistors are directly connected, thereby providing a high A frequency oscillation circuit that is not affected by the impedance of a grounded capacitor or has no characteristics such as a drop in the S/N ratio.

FIG. 1 is a circuit diagram showing a high-frequency oscillation circuit according to a first embodiment of the present invention;

FIG. 2 is a circuit diagram showing another example of the high-frequency oscillation circuit of the first embodiment;

3 is a circuit diagram showing a high-frequency oscillation circuit according to a second embodiment of the present invention;

FIG. 4 is a circuit diagram showing another example of the high-frequency oscillation circuit of the second embodiment;

5 is a circuit diagram showing a high-frequency oscillation circuit according to a third embodiment of the present invention;

FIG. 6 is a circuit diagram showing another example of the high-frequency oscillation circuit of the third embodiment;

7 is a circuit diagram showing a high-frequency oscillation circuit according to a fourth embodiment of the present invention;

FIG. 8 is a circuit diagram showing another example of the high-frequency oscillation circuit of the fourth embodiment;

9 is a circuit diagram showing a high-frequency oscillation circuit according to a fifth embodiment of the present invention;

10 is a circuit diagram showing a high-frequency oscillation circuit according to a sixth embodiment of the present invention;

Fig. 11 shows the structure of the high-frequency oscillation circuit in the fifth and sixth embodiments of the present invention;

12 is a circuit diagram showing a high-frequency oscillation circuit according to a seventh embodiment of the present invention;

13 is a circuit diagram showing a high-frequency oscillation circuit according to an eighth embodiment of the present invention;

FIG. 14 is a diagram showing the structure of a resonant circuit in seventh and eighth embodiments of the present invention;

Fig. 15 shows the structure of an example of the high-frequency oscillation circuit in the seventh and eighth embodiments of the present invention;

Fig. 16 shows the structure of another example of the high frequency oscillating circuit in the seventh and eighth embodiments of the present invention;

17 is a circuit diagram of another example of the high-frequency oscillation circuit according to the first embodiment of the present invention;

FIG. 18 is a circuit diagram of another example of the high-frequency oscillation circuit according to the first embodiment of the present invention; and

Fig. 19 is a circuit diagram showing a conventional high-frequency oscillation circuit.

The present invention will be described below with reference to the drawings showing the embodiments.

(Example 1)

FIG. 1 is a circuit diagram showing a high-frequency oscillation circuit according to a first embodiment of the present invention. In this figure, 1 and 17 are oscillation transistors; 2, 3, 4, 18, 35 and 36 are capacitors; 5 and 21 are resonator coupling capacitors; 6 and 22 are output coupling capacitors; 7 are resonators; 23 is a varactor coupling capacitor; 9 and 24 are varactors; 11, 12, 13, 26, 27 and 28 are bias resistors; 14 and 29 are varactor bias choke coils; 15 and 16 are High-frequency output terminals; 10, 25 and 30 are high-frequency choke coils; 31 and 32 are bypass capacitors; 33 is a tuning voltage power supply terminal; 34 is a bias power supply terminal. In this case, the oscillation transistor 1 is a first oscillation transistor, and the oscillation transistor 17 is a second oscillation transistor. Capacitors 4 and 3 have sufficiently low impedance (below a certain value) at the oscillation frequency to allow oscillation. This applies to each of the following examples.

The high-frequency oscillation circuit constructed according to the first embodiment operates as follows.

In FIG. 1 , bases of oscillation transistors 1 and 17 are respectively connected via capacitors 4 having sufficiently low impedance in the oscillation frequency band. Capacitors 2 and 18 are connected to transistors 1 and 17 as collector-emitter capacitive elements, the values of which are chosen to provide an optimum S/N ratio in the oscillation frequency band. Capacitors 35 and 36 are connected as collector-base capacitive elements to transistors 1 and 17, the values of which are chosen to provide the optimum S/N ratio in the oscillation frequency band. In addition, a capacitor 3 is connected between the emitters of the transistors 1 and 17, the element value of which is selected to provide an optimum S/N ratio in the oscillation frequency band. Furthermore, the resonator 7 connected via the resonator coupling capacitors 5 and 21 is a half-length resonator whose terminals are open. Since the midpoint of the resonator is equivalent to being used as a short-circuit point to ground, the resonator 7 is equivalent to being connected between the collector and the base of the transistor 1 via the resonator coupling capacitor 5 as an inductive element and connected to the transistor via the capacitor 21. 17 between the collector and the base as an inductive element.

Furthermore, each of the varactors 9 and 24 is connected to the resonator 7 via varactor coupling capacitors 8 and 23, respectively. In addition, since the varactor bias choke coils 14 and 29 provide ground potential to the anodes of the varactor diodes 9 and 24 in a direct current manner, the voltage value applied to the tuning voltage power supply terminal 33 via the high frequency choke coil 30 changes. The capacitance values of varactor diodes 9 and 24 are increased to change the oscillation frequency.

Thus, in the circuit of FIG. 1, two grounded base vibration (clap) oscillating circuits use a half-length resonator for oscillating operation to provide oscillating signals whose phases are shifted by 180° from each other, through the output coupling capacitor 6 and 22 take their output from between high frequency output terminals 15 and 16 as a differential signal output between the two circuits.

According to this structure, the base-ground capacitor and the emitter-ground capacitor, which are usually connected between the oscillation transistor and the ground, are not connected to the ground pattern of the mounting circuit board, but are directly connected between the base and the emitter-ground of the two oscillation transistors. between the emitters. Thus, a differential oscillation operation can be performed at a high frequency without using the ground pattern on the mounting circuit board. Accordingly, it is possible to provide a high-frequency oscillation circuit that is not affected by a potential difference generated in a ground pattern on a mounted circuit board, or has no characteristics such as a drop in the S/N ratio even when external electromagnetic interference is generated .

Fig. 2 is a circuit diagram of another example of the high-frequency oscillation circuit of this embodiment. In this structure, 1 and 17 are oscillation transistors; 2, 3, 4, 18, 35 and 36 are capacitors; 5 and 21 are resonator coupling capacitors; 6 and 22 are output coupling capacitors; 7 is a resonator; 8 and 23 is a varactor coupling capacitor; 9 and 24 are varactors; 11, 12, 13, 26 and 28 are bias resistors; 14 and 29 are varactor bias choke coils; 15 and 16 are high frequency Output terminals; 10, 25 and 30 are high-frequency choke coils; 31 and 32 are bypass capacitors; 33 is a tuning voltage power supply terminal; 34 is a bias power supply terminal.

The high frequency oscillating circuit constructed according to the present embodiment operates as follows.

In FIG. 2, the bases of oscillation transistors 1 and 17 are directly connected together. Capacitors 2 and 18 are connected as collector-emitter capacitive elements to transistors 1 and 17 respectively, the values of which are chosen to provide the optimum S/N ratio within the oscillation frequency band. Capacitors 35 and 36 are connected as collector-base capacitive elements to transistors 1 and 17, the values of which are chosen to provide the optimum S/N ratio within the oscillation frequency band.

In addition, a capacitor 3 is connected between the emitters of the transistors 1 and 17, the element value of which is selected to provide an optimum S/N ratio within the oscillation frequency band. Furthermore, the resonator 7 connected via the resonator coupling capacitors 5 and 21 is a half-length resonator whose terminals are open. Since the midpoint of the resonator is equivalent to being used as a short-circuit point to ground, the resonator 7 is equivalent to being connected between the collector and the base of the transistor 1 via the resonator coupling capacitor 5 as an inductive element and connected to the transistor via the capacitor 21. 17 between the collector and the base as an inductive element.

Furthermore, each of the varactors 9 and 24 is connected to the resonator 7 via varactor coupling capacitors 8 and 23, respectively. In addition, since the varactor bias choke coils 14 and 29 provide ground potential to the anodes of the varactor diodes 9 and 24 in a direct current manner, the voltage value applied to the tuning voltage power supply terminal 33 via the high frequency choke coil 30 changes. The capacitance values of varactor diodes 9 and 24 are increased to change the oscillation frequency.

Thus, in the circuit of FIG. 2, two grounded base-vibrating oscillating circuits use a half-length resonator for oscillating operation to provide oscillating signals whose phases are shifted by 180° from each other through output coupling capacitors 6 and 22 from high frequency Their output is obtained between output terminals 15 and 16 as a differential signal output between the two circuits.

According to this structure, the bases of the oscillating transistors are directly connected to eliminate an impedance element that acts as a noise source in the base at high frequencies without connecting a base-ground capacitor that is usually connected between the bases of the oscillating transistors. As a result, a high frequency oscillating circuit free from characteristics such as a drop in the S/N ratio can be provided.

(Example 2)

FIG. 3 is a circuit diagram showing a high frequency oscillation circuit according to a second embodiment of the present invention. In this figure, 1 and 17 are oscillation transistors; 2, 3, 4, 18, 35 and 36 are capacitors; 5 and 21 are resonator coupling capacitors; 6 and 22 are output coupling capacitors; 7 are resonators; 23 is a varactor coupling capacitor; 9 and 24 are varactors; 11, 12, 13, 26, 27 and 28 are bias resistors; 14 and 29 are varactor bias choke coils; 15 and 16 are High frequency output terminal; 30 is a high frequency choke coil; 31 and 32 are bypass capacitors; 33 is a tuning voltage power supply terminal; 34 is a bias voltage power supply terminal.

The high-frequency oscillation circuit constructed according to the second embodiment operates as follows.

In FIG. 3 , collectors of oscillation transistors 1 and 17 are connected via capacitors 4 having sufficiently low impedance in the oscillation frequency band, respectively. Capacitors 2 and 18 are connected as base-emitter capacitive elements to transistors 1 and 17, the values of which are chosen to provide an optimum S/N ratio in the oscillation frequency band. Capacitor 3 is connected between the emitters of transistors 1 and 17, the element value of which is selected to provide an optimum S/N ratio in the oscillation frequency band. Furthermore, the resonator 7 connected via the resonator coupling capacitors 5 and 21 is a half-length resonator whose terminals are open. Since the midpoint of the resonator is equivalent to being used as a short-circuit point to ground, the resonator 7 is equivalent to being connected between the base and the collector of the transistor 1 via the resonator coupling capacitor 5 as an inductive element and connected to the transistor via the capacitor 21. 17 between the base and the collector as an inductive element.

Furthermore, each of the varactors 9 and 24 is connected to the resonator 7 via varactor coupling capacitors 8 and 23, respectively. In addition, since the varactor bias choke coils 14 and 29 provide ground potential to the anodes of the varactor diodes 9 and 24 in a direct current manner, the voltage value applied to the tuning voltage power supply terminal 33 via the high frequency choke coil 30 changes. The capacitance values of varactor diodes 9 and 24 are increased to change the oscillation frequency.

Thus, in the circuit of FIG. 3, two grounded collector oscillating oscillating circuits operate oscillatingly with a half-length resonator to provide oscillating signals whose phases are shifted by 180° from each other, and which are transmitted from high frequency through output coupling capacitors 6 and 22. Their output is obtained between output terminals 15 and 16 as a differential signal output between the two circuits.

According to this structure, the collector-ground capacitor and the emitter-ground capacitor, which are usually connected between the oscillation transistor and the ground, are not connected to the ground pattern of the mounting circuit board, but are directly connected between the collector and the ground of the two oscillation transistors. between the emitters. Thus, a differential oscillation operation can be performed at a high frequency without using the ground pattern on the mounted circuit board, thereby providing a high-frequency oscillation circuit that is not affected by a potential difference generated in the ground pattern on the mounted circuit board. influence, or there are no characteristics such as S/N ratio drop even when external electromagnetic interference is generated.

Fig. 4 is a circuit diagram of another example of the high-frequency oscillation circuit of the second embodiment. In this structure, 1 and 17 are oscillation transistors; 2, 3 and 18 are capacitors; 5 and 21 are resonator coupling capacitors; 6 and 22 are output coupling capacitors; 7 is a resonator; 8 and 23 are varactor coupling Capacitors; 9 and 24 are varactor diodes; 11, 12, 13, 26, 27 and 28 are bias resistors; 14 and 29 are varactor bias choke coils; 15 and 16 are high-frequency output terminals; 30 31 and 32 are bypass capacitors; 33 is a tuning voltage power supply terminal; 34 is a bias power supply terminal.

The high-frequency oscillation circuit constructed according to the second embodiment operates as follows.

In FIG. 4, the collectors of oscillation transistors 1 and 17 are directly connected together. Capacitors 2 and 18 are connected as base-emitter capacitive elements to transistors 1 and 17 respectively, the values of which are chosen to provide the optimum S/N ratio within the oscillation frequency band.

Capacitor 3 is connected between the emitters of transistors 1 and 17, the element values of which are selected to provide an optimum S/N ratio within the oscillation frequency band. Furthermore, the resonator 7 connected via the resonator coupling capacitors 5 and 21 is a half-length resonator whose terminals are open. Since the midpoint of the resonator is equivalent to being used as a short-circuit point to ground, the resonator 7 is equivalent to being connected between the base and the collector of the transistor 1 via the resonator coupling capacitor 5 as an inductive element and connected to the transistor via the capacitor 21. 17 between the base and the collector as an inductive element.

Furthermore, each of the varactors 9 and 24 is connected to the resonator 7 via varactor coupling capacitors 8 and 23, respectively. In addition, since the varactor bias choke coils 14 and 29 provide ground potential to the anodes of the varactor diodes 9 and 24 in a direct current manner, the voltage value applied to the tuning voltage power supply terminal 33 via the high frequency choke coil 30 changes. The capacitance values of varactor diodes 9 and 24 are increased to change the oscillation frequency.

Thus, in the circuit of FIG. 4, two grounded collector vibration oscillation circuits use a half-length resonator for oscillation operation to provide oscillation signals with phase shifts of 180° from each other through output coupling capacitors 6 and 22 from high Their output is obtained between the frequency output terminals 15 and 16 as a differential signal output between the two circuits.

According to this structure, the collector of the oscillation transistor is directly connected to eliminate an impedance element that acts as a noise source in the collector at high frequencies, without connecting a collector-to-ground capacitor normally connected between collectors of the oscillation transistor. As a result, a high frequency oscillating circuit free from characteristics such as a drop in the S/N ratio can be provided.

(Example 3)

FIG. 5 is a circuit diagram showing a high-frequency oscillation circuit according to a third embodiment of the present invention. In this figure, 41 and 42 are buffer amplifier transistors; 43 and 44 are bias resistors; 45 is a capacitor; 32 is a bypass capacitor; 39 and 40 are high frequency choke coils; 37 and 38 are interstage coupling capacitors ; 6 and 22 are output coupling capacitors; 34 is a bias power supply; 15 and 16 are high-frequency output terminals. In this case, the oscillation transistor 1 is a first oscillation transistor, the oscillation transistor 17 is a second oscillation transistor, the buffer amplifier transistor 41 is a first buffer amplifier transistor, and the buffer amplifier transistor 42 is a second buffer amplifier transistor. Other elements are the same as those in Fig. 1 .

The high frequency oscillating circuit constructed according to the third embodiment operates as follows.

In FIG. 5, like the first embodiment, oscillation transistors 1 and 17 constitute a grounded base oscillation oscillation circuit and perform an oscillation operation by supplying oscillation signals whose phases are shifted from each other by 180°. Its output is amplified by buffer amplifier transistors 41 and 42 via interstage coupling capacitors 37 and 38 , and then obtained as a differential signal output from between high frequency output terminals 15 and 16 via output coupling capacitors 6 and 22 .

The buffer amplifier transistors 41 and 42 have the form of a grounded emitter differential amplifier circuit. As a ground capacitor, a capacitor 45 having sufficiently low impedance in the oscillation frequency band is directly connected to the emitters of the two buffer amplifier transistors (as in the oscillation transistors 1 and 17).

As mentioned above, the emitter ground capacitor usually connected between the buffer amplifier transistor and the ground is not connected to the ground pattern on the mounting circuit board, but is directly connected between the emitters of the two oscillation transistors. Thus, the oscillating circuit and the buffer amplifier section can perform differential circuit operation at high frequencies without using the ground pattern on the mounted circuit board, thereby providing a high-frequency oscillating circuit that is not affected by the ground pattern on the mounted circuit board. There is no influence of the potential difference generated in the pattern, or even when external electromagnetic interference is generated, there is no characteristic such as a drop in the S/N ratio.

Further, in the DC bias circuit, the collectors of the oscillation transistors 1 and 17 are connected to the emitters of the buffer amplifier transistors 41 and 42 through the high frequency choke coils 10 and 25 . Thus, the same collector current path is used for the buffer amplifier transistor 41 and the oscillation transistor 1 , and likewise, the same collector current path is used for the buffer amplifier transistor 42 and the oscillation transistor 17 .

This configuration provides a high-frequency oscillation circuit that reduces current consumption compared to a circuit that uses different current paths to supply collector current to the oscillation and buffer amplifier transistors.

Fig. 6 is a circuit diagram showing another example of the high frequency oscillation circuit according to the third embodiment of the present invention. In this figure, 41 and 42 are buffer amplifier transistors; 11, 26, 43 and 44 are bias resistors; 32 are bypass capacitors; 39 and 40 are high frequency choke coils; 37 and 38 are interstage coupling capacitors ; 6 and 22 are output coupling capacitors; 34 is a bias power supply; 15 and 16 are high-frequency output terminals. Other elements are the same as those in Fig. 2 . In this case, the interstage coupling capacitors 37 and 38 are the sixth and seventh capacitors, and the output coupling capacitors 6 and 22 are the eighth and ninth capacitors.

The high frequency oscillating circuit constructed according to the third embodiment operates as follows.

In FIG. 6, like the first embodiment, oscillation transistors 1 and 17 constitute a grounded base oscillation oscillation circuit and perform an oscillation operation by supplying oscillation signals whose phases are shifted from each other by 180°. Its output is amplified by buffer amplifier transistors 41 and 42 via interstage coupling capacitors 37 and 38 , and then obtained as a differential signal output from between high frequency output terminals 15 and 16 via output coupling capacitors 6 and 22 .

The buffer amplifier transistors 41 and 42 have the form of a grounded emitter differential amplifier circuit. The emitters of the two buffer amplifier transistors are directly connected together.

As mentioned above, instead of connecting the emitter-to-ground capacitor that is normally connected between two buffer amplifier transistors, connect the emitters of the two buffer amplifier transistors directly together to eliminate the A grounded capacitor with an impedance component in the part, thereby providing a high-frequency oscillation circuit without characteristics such as a drop in the S/N ratio.

Further, in the DC bias circuit, the collectors of the oscillation transistors 1 and 17 are connected to the emitters of the buffer amplifier transistors 41 and 42 through the high frequency choke coils 10 and 25, that is, the first and second inductors. Thus, the same collector current path is used for the buffer amplifier transistor 41 and the oscillation transistor 1 , and likewise, the same collector current path is used for the buffer amplifier transistor 42 and the oscillation transistor 17 .

This configuration provides a high-frequency oscillation circuit that reduces current consumption compared to a circuit that uses different current paths to supply collector current to the oscillation and buffer amplifier transistors.

(Example 4)

Fig. 7 is a circuit diagram showing a high frequency oscillation circuit according to a fourth embodiment of the present invention. In this figure, 41 and 42 are buffer amplifier transistors; 43 and 44 are bias resistors; 32 are bypass capacitors; 39 and 40 are high-frequency choke coils; 37 and 38 are interstage coupling capacitors; 6 and 22 Is the output coupling capacitor; 34 is the bias power supply; 15 and 16 are high-frequency output. In this case, the oscillation transistor 1 is a first oscillation transistor, the oscillation transistor 17 is a second oscillation transistor, the buffer amplifier transistor 41 is a first buffer amplifier transistor, and the buffer amplifier transistor 42 is a second buffer amplifier transistor. Other elements are the same as those in FIG. 3 .

The high-frequency oscillation circuit constructed according to the fourth embodiment operates as follows.

In FIG. 7, like the second embodiment, oscillation transistors 1 and 17 constitute a grounded collector oscillation oscillation circuit and perform an oscillation operation by supplying oscillation signals whose phases are shifted from each other by 180°. Its output is amplified by buffer amplifier transistors 41 and 42 via interstage coupling capacitors 37 and 38 , and then obtained as a differential signal output from between high frequency output terminals 15 and 16 via output coupling capacitors 6 and 22 .

The buffer amplifier transistors 41 and 42 have the form of a grounded emitter differential amplifier circuit. The capacitor 4 for grounding the collectors of the oscillation transistors 1 and 17 can also be used as a ground capacitor for the buffer amplifier transistors 41 and 42 .

As mentioned above, the emitter ground capacitor usually connected between the buffer amplifier transistor and the ground is not connected to the ground pattern on the mounting circuit board, but is directly connected between the emitters of the two oscillation transistors. Thus, the oscillating circuit and the buffer amplifier section can perform differential circuit operation at high frequencies without using the ground pattern on the mounted circuit board, thereby providing a high-frequency oscillating circuit that is not affected by the ground pattern on the mounted circuit board. There is no influence of the potential difference generated in the pattern, or even when external electromagnetic interference is generated, there is no characteristic such as a drop in the S/N ratio.

Furthermore, the collectors of the oscillation transistors 1 and 17 are connected to the emitters of the buffer amplifier transistors 41 and 42 in the DC bias circuit. Thus, the same collector current path is used for the buffer amplifier transistor 41 and the oscillation transistor 1 , and likewise, the same collector current path is used for the buffer amplifier transistor 42 and the oscillation transistor 17 .

This configuration provides a high-frequency oscillation circuit that reduces current consumption compared to a circuit that uses different current paths to supply collector current to the oscillation and buffer amplifier transistors.

Fig. 8 is a circuit diagram showing another example of a high frequency oscillation circuit according to a fourth embodiment of the present invention. In this figure, 41 and 42 are buffer amplifier transistors; 43, 44, 46 and 47 are bias resistors; 32 are bypass capacitors; 39 and 40 are high frequency choke coils; 37 and 38 are interstage coupling capacitors ; 6 and 22 are output coupling capacitors; 34 is a bias power supply; 15 and 16 are high-frequency output terminals. Other elements are the same as those in FIG. 4 .

The high-frequency oscillation circuit constructed according to the fourth embodiment operates as follows.

In FIG. 8, like the second embodiment, oscillation transistors 1 and 17 constitute a grounded collector oscillation oscillation circuit and perform an oscillation operation by supplying oscillation signals whose phases are shifted from each other by 180°. Its output is amplified by buffer amplifier transistors 41 and 42 via interstage coupling capacitors 37 and 38 , and then obtained as a differential signal output from between high frequency output terminals 15 and 16 via output coupling capacitors 6 and 22 .

The buffer amplifier transistors 41 and 42 have the form of a grounded emitter differential amplifier circuit. The emitters of the two buffer amplifier transistors are directly connected together.

As mentioned above, instead of connecting the emitter ground capacitor that is usually connected between two buffer amplifier transistors, the emitters of the two buffer amplifier transistors are directly connected together, thus, the oscillation circuit and the buffer amplifier can be used at high frequencies. The amplifier section performs a differential circuit operation without using a ground capacitor, thereby providing a high-frequency oscillation circuit free from characteristics such as a drop in the S/N ratio due to the impedance of the ground capacitor.

Furthermore, the collectors of the oscillation transistors 1 and 17 are connected to the emitters of the buffer amplifier transistors 41 and 42 in the DC bias circuit. Thus, the same collector current path is used for the buffer amplifier transistor 41 and the oscillation transistor 1 , and likewise, the same collector current path is used for the buffer amplifier transistor 42 and the oscillation transistor 17 .

This configuration provides a high-frequency oscillation circuit that reduces current consumption compared to a circuit that uses different current paths to supply collector current to the oscillation and buffer amplifier transistors.

The circuit structure according to this embodiment is only schematic, and the structure of the additional circuit related to the transistor is not limited in this respect, as long as the bases or collectors of the two oscillation transistors are directly connected together, and the emitters of the two buffer amplifier transistors are directly connected together. connected together so that they are not affected by the impedance of the capacitor to ground.

(Example 5)

Fig. 9 is a circuit diagram showing a high-frequency circuit of a fifth embodiment of the present invention. According to the present embodiment, the resonance circuit 56 and the oscillation circuit 55 are connected separately from each other. In Fig. 9, 1 and 17 are oscillation transistors as first and second oscillation transistors; 2, 35, 4, 18, 36 and 3 are capacitors; 6 and 22 are output coupling capacitors; 11, 12, 13, 26 , 27 and 28 are bias resistors; 15 and 16 are high frequency output terminals; 10 and 25 are high frequency choke coils; 34 are bias power supply terminals; 54 are ground terminals; 52 and 53 are connections to the resonant circuit Point; 55 is a negative resistance generating integrated circuit as an external circuit for generating negative resistance.

Furthermore, in Fig. 9, 5 and 21 are resonator coupling capacitors; 7 is a resonator; 8 and 23 are varactor coupling capacitors; 9 and 24 are varactor diodes; 14 and 29 are varactor bias voltage chokes 30 is a high-frequency choke coil; 31 is a bypass capacitor; 33 is a tuning voltage power supply terminal; 51 is a ground terminal; 56 is a resonant circuit. Connection points 49 and 50 of the negative resistance generating integrated circuits connected to capacitors 5 and 21, respectively, are first and second connection points.

The oscillation circuit using the resonance circuit of the structure according to the fifth embodiment of the present invention operates as follows.

In FIG. 9, the bases of the oscillation transistors 1 and 17 are connected together via a capacitor 4 having sufficiently low impedance in the oscillation frequency band. Capacitors 2 and 18 are connected to transistors 1 and 17 as collector-emitter capacitive elements, the values of which are chosen to provide an optimum S/N ratio in the oscillation frequency band. Capacitors 35 and 36 are connected as collector-base capacitive elements to transistors 1 and 17, the values of which are chosen to provide the optimum S/N ratio in the oscillation frequency band. In addition, a capacitor 3 is connected between the emitters of the transistors 1 and 17, the element value of which is selected to provide an optimum S/N ratio in the oscillation frequency band. Furthermore, the resonator 7 connected in the resonance circuit 56 via the resonator coupling capacitors 5 and 21 is a half-wave resonator whose junction is open. Since the midpoint of the resonator is equivalent to being used as a short-circuit point to ground, the resonator 7 is equivalent to being connected between the collector and the base of the transistor 1 via the resonator coupling capacitor 5 as an inductive element and connected to the transistor via the capacitor 21. 17 between the collector and the base as an inductive element.

Furthermore, each of the varactors 9 and 24 is connected to the resonator 7 via varactor coupling capacitors 8 and 23, respectively. In addition, since the varactor diode bias choke coils 14 and 29 provide ground potential to the anodes of the varactor diodes 9 and 24 via the ground terminal 51 in a DC manner, the tuning voltage power supply terminal 33 is applied via the high frequency choke coil 30 . The voltage value applied to the cathodes of the varactor diodes 9 and 24 changes the capacitance value of the varactor diodes 9 and 24 to change the oscillation frequency.

Thus, in the circuit of FIG. 9, two grounded base vibration oscillation circuits use a half-length resonator for oscillation operation to provide oscillation signals whose phases are shifted by 180° from each other, and output coupling capacitors 6 and 22 from high Their output is obtained between the frequency output terminals 15 and 16 as a differential signal output between the two circuits.

The negative resistance generating integrated circuit 55 is formed as an integrated circuit on a semiconductor chip by an IC process.

On the other hand, the resonant circuit 56 module is formed separately from the negative resistance generating integrated circuit 55 so as to be connected to the connecting points 52 and 53 of the resonant circuit in the negative resistance generating integrated circuit 55 via the connection points 49 and 50 of the negative resistance generating integrated circuit 55. .

Thus, contrary to the conventional resonance circuit used for the oscillation circuit IC, the resonance circuit according to the present embodiment is not disposed on the oscillation circuit IC forming the negative resistance generating circuit portion, but provided as a separate module. Thus, the Q factor of the formed resonance circuit is not lowered to provide a high S/N ratio to the oscillation circuit IC.

In addition, when the negative resistance generating integrated circuit 55 is constituted as described above, the base ground capacitor and the emitter-ground capacitor connected between the oscillation transistor and the ground are not connected to the ground on the circuit board on which the negative resistance generating circuit is mounted. line pattern, but directly connected between the base and emitter of the two oscillating transistors. Thus, a differential oscillation operation can be performed at a high frequency without using the ground pattern on the mounted circuit board, thereby providing a high-frequency oscillation circuit that is not affected by a potential difference generated in the ground pattern on the mounted circuit board. influence or characteristics such as S/N ratio drop even when external electromagnetic interference is generated.

As long as the external negative resistance generating circuit is formed inside the integrated circuit, it is not limited to the structure in FIG. 9 .

(Example 6)

10 is a circuit diagram showing an oscillation circuit using a resonance circuit according to a sixth embodiment of the present invention. In this figure, 1 and 17 are oscillation transistors as first and second oscillation transistors; 2, 4, 18, and 3 are capacitors; 6 and 22 are output coupling capacitors; 11, 12, 13, 26, 27, and 28 15 and 16 are high-frequency output terminals; 10 and 25 are high-frequency choke coils; 34 is the bias power supply terminal; 54 is the ground terminal; 52 and 53 are the connection points of the resonant circuit; 55 is the negative Resistors create integrated circuits.

Furthermore, in FIG. 10, 56 is a resonance circuit having the same structure as the resonance circuit according to the first embodiment described above.

The oscillation circuit using the resonance circuit constructed according to the sixth embodiment operates as follows.

In FIG. 10 , the collectors of the oscillation transistors 1 and 17 are connected together via a capacitor 4 having sufficiently low impedance in the oscillation frequency band. Capacitors 2 and 18 are connected as base-emitter capacitive elements to transistors 1 and 17, the values of which are chosen to provide an optimum S/N ratio in the oscillation frequency band. In addition, a capacitor 3 is connected between the emitters of the transistors 1 and 17, the element value of which is selected to provide an optimum S/N ratio in the oscillation frequency band. Furthermore, the resonator 7 connected in the resonance circuit 56 via the resonator coupling capacitors 5 and 21 is a half-wave resonator whose junction is open. Since the midpoint of the resonator is equivalent to being used as a short-circuit point to ground, the resonator 7 is equivalent to being connected between the collector and the base of the transistor 1 via the resonator coupling capacitor 5 as an inductive element and connected to the transistor via the capacitor 21. 17 between the collector and the base as an inductive element.

Furthermore, each of the varactors 9 and 24 is connected to the resonator 7 via varactor coupling capacitors 8 and 23, respectively. In addition, since the varactor diode bias choke coils 14 and 29 provide ground potential to the anodes of the varactor diodes 9 and 24 via the ground terminal 51 in a DC manner, the tuning voltage power supply terminal 33 is applied via the high frequency choke coil 30 . The voltage value to the cathodes of the varactor diodes 9 and 24 changes the capacitance value of the varactor diodes 9 and 24 to change the oscillation frequency.

Thus, in the circuit of FIG. 10, two grounded collector vibration oscillation circuits use a half-length resonator for oscillation operation to provide oscillation signals whose phases are shifted by 180° from each other through output coupling capacitors 6 and 22 from high Their output is obtained between the frequency output terminals 15 and 16 as a differential signal output between the two circuits.

The negative resistance generating integrated circuit 55 is formed as an integrated circuit on a semiconductor chip by an IC process.

On the other hand, the resonant circuit 56 module is formed separately from the negative resistance generating integrated circuit 55 so as to be connected to the connecting points 52 and 53 of the resonant circuit in the negative resistance generating integrated circuit 55 via the connection points 49 and 50 of the negative resistance generating integrated circuit 55. .

Then, as in the first embodiment of the present invention, contrary to the conventional resonance circuit used for the oscillation circuit IC, the resonance circuit according to the present embodiment is not disposed on the oscillation circuit IC forming a negative resistance generating circuit portion, but is set as separate modules. Thus, the Q factor of the formed resonance circuit is not lowered to provide a high S/N ratio to the oscillation circuit IC.

In addition, when the negative resistance generating integrated circuit 55 is constituted as described above, the collector ground capacitor and the emitter ground capacitor connected between the oscillation transistor and the ground are not connected to the ground pattern on the circuit board on which the negative resistance generating circuit is mounted. , but directly connected between the collector and emitter of the two oscillator transistors. Thus, a differential oscillation operation can be performed at a high frequency without using the ground pattern on the mounted circuit board, thereby providing a high-frequency oscillation circuit that is not affected by a potential difference generated in the ground pattern on the mounted circuit board. influence or characteristics such as S/N ratio drop even when external electromagnetic interference is generated.

As long as the negative resistance generating circuit 55, that is, the external negative resistance generating circuit is formed inside the integrated circuit, it is not limited to the structure in FIG. 10 .

FIG. 11 shows the configuration of an oscillation circuit using the resonance circuits according to the fifth and sixth embodiments. In the figure, 69 is an IC package including the negative resistance generating integrated circuit 55 according to the fifth and sixth embodiments.

Reference numerals 70 to 75 denote IC package connection terminals, which are connected inside the IC package 69 to the connection points 52 and 53 of the negative resistance generating integrated circuit 55 (connected to the resonance circuit) according to the fifth and sixth embodiments, the IC package connection The terminal is also connected to the bias voltage supply terminal 34, the ground terminal 54 and the high frequency output terminals 15 and 16.

Reference numeral 64 denotes a resonance circuit block formed of the resonance circuits 56 according to the fifth and sixth embodiments. The sides 65 and 66 of the resonance circuit 56 are terminal electrodes formed by the connection points 49 and 50 of the resonance circuit 56 (connected to the negative resistance generating IC) according to the fifth and sixth embodiments.

Reference numerals 67 and 68 denote connection patterns for connecting the negative resistance generating integrated circuit in the IC package 69 to the resonance circuit forming the resonance circuit block 64 to constitute the oscillation circuit.

For example, through a strip line resonator formed on a dielectric substrate, a capacitor including a coupling capacitance between conductive patterns formed in upper and lower parts of a dielectric substrate, or a capacitor including a conductive pattern formed on a dielectric substrate The resonant circuit module 64 is realized by an inductor. In this case, it is preferable that the dielectric substrate has a high Q factor and that green sheets having a high dielectric constant are laminated using a lamination process to provide excellent characteristics and a small size. Varactor diodes 9 and 24 are mounted as bare chips on a dielectric substrate.

The above structure can realize the resonant circuit as a small resonant circuit module with a high Q factor, which is connected to an external circuit mounted in an IC package, and the negative resistance generating circuit part is constituted as an IC to provide a high overall S/N ratio. small oscillating circuit.

(Example 7)

12 is a circuit diagram showing an oscillation circuit having a resonance circuit of a seventh embodiment of the present invention. In the figure, 1 and 17 are oscillation transistors as first and second oscillation transistors; 2, 35, 4, 18, 36 and 3 are capacitors; 6 and 22 are output coupling capacitors; 11, 12, 13, 26 , 27 and 28 are bias resistors; 15 and 16 are high-frequency output terminals; 10 and 25 are high-frequency choke coils; 34 are bias power supply terminals; 54 are ground terminals; 5 and 21 are resonator coupling capacitors; 8 and 23 are varactor diode coupling capacitors; 14 and 29 are varactor diode bias choke coils; 30 is a high-frequency choke coil; 33 is a tuning voltage power supply terminal; 86 is a ground terminal; 81, 82, 83, 84 and 85 are connection points of the resonance circuit; 57 is a negative resistance generating integrated circuit as an external circuit for generating negative resistance.

Furthermore, in Fig. 12, 7 is a resonator; 9 and 24 are varactor diodes; The second connection point; 58 is the resonant circuit.

Connection points 81, 82, 83, 84 and 85 of the negative resistance generating integrated circuit 57 connected to the resonant circuit are respectively connected to connection points 59, 60, 61, 62 and 63 of the resonant circuit 58 (connected to the negative resistance generating integrated circuit). .

The operation of the oscillation circuit using the above-structured resonance circuit according to the seventh embodiment is exactly the same as that in the fifth embodiment of the present invention, so its description is omitted.

The seventh embodiment differs from the fifth embodiment in that the resonant circuit 58 arranged outside the negative resistance generating circuit 57 integrated by IC process is constituted only by the resonator 7 and the varactor diodes 9 and 24 .

This is because if an IC process is used to form the elements of the resonant circuit 56 according to the fifth embodiment shown in FIG. value factor.

Thus, unlike a conventional resonance circuit used for an oscillation circuit IC, the resonance circuit according to the present embodiment is not disposed on the oscillation circuit IC in which a negative resistance generating circuit portion is formed. Furthermore, when an element is formed using an IC process, resonators and varactors, which are significantly affected by Q factor reduction, form a module separate from the negative resistance generating circuit. As a result, the resonant circuit thus constituted can avoid lowering of the Q factor, thereby realizing a high S/N ratio for the oscillating circuit IC.

Furthermore, by constituting the negative resistance generating integrated circuit 57 as described above, the base ground capacitor and the emitter-ground capacitor normally connected between the oscillating transistor and the ground are not connected to the circuit board on which the negative resistance generating circuit is mounted. Instead, it is directly connected between the base and emitter of the two oscillating transistors. Thus, as in the first embodiment, a differential oscillation operation can be performed at a high frequency without using the ground pattern on the mounted circuit board, thereby providing a high-frequency oscillation circuit that is not affected by the ground pattern on the mounted circuit board. There are no characteristics such as a drop in the S/N ratio due to the influence of a potential difference generated in a line pattern or even when external electromagnetic interference is generated.

As long as the external negative resistance generating circuit is formed inside the integrated circuit, it is not limited to the structure in FIG. 12 .

(Embodiment 8)

13 is a circuit diagram showing an oscillation circuit using a resonance circuit of an eighth embodiment of the present invention. In this figure, 1 and 17 are oscillation transistors as first and second oscillation transistors; 2, 4, 18, and 3 are capacitors; 6 and 22 are output coupling capacitors; 11, 12, 13, 26, 27, and 28 15 and 16 are high frequency output terminals; 10 and 25 are high frequency choke coils; 34 are bias power supply terminals; 54 are ground terminals; 5 and 21 are resonator coupling capacitors; 8 and 23 are Varactor diode coupling capacitor; 14 and 29 are varactor diode bias choke coils; 30 is a high frequency choke coil; 33 is a tuning voltage power supply terminal; 86 is a ground terminal; 81, 82, 83, 84 and 85 resonant circuits The connecting point; 57 is a negative resistance generation integrated circuit.

Furthermore, in Fig. 13, 7 is a resonator; 9 and 24 are varactor diodes; The second connection point; 58 is the resonant circuit.

The connection points 81, 82, 83, 84 and 85 connected to the negative resistance generating integrated circuit 57 of the resonant circuit are respectively connected to the connecting points 59, 60, 61, 62 and 85 of the resonant circuit 58 (connected to the negative resistance generating integrated circuit). 63.

The operation of the oscillation circuit using the above-structured resonance circuit according to the eighth embodiment is exactly the same as that in the sixth embodiment of the present invention, so its description is omitted.

The eighth embodiment differs from the sixth embodiment in that the resonant circuit 58 arranged outside the negative resistance generating circuit 57 integrated by IC process is composed of only the resonator 7 and the varactor diodes 9 and 24 .

Like the resonance circuit 58 in the seventh embodiment, this is because if an IC process is used to form the elements of the resonance circuit 56 according to the sixth embodiment shown in FIG. The reduction of the value factor will obviously affect the Q factor of the resonant circuit.

Thus, unlike a conventional resonance circuit used for an oscillation circuit IC, the resonance circuit according to the present embodiment is not disposed on the oscillation circuit IC in which a negative resistance generating circuit portion is formed. Furthermore, when an element is formed using an IC process, resonators and varactors, which are significantly affected by Q factor reduction, form a module separate from the negative resistance generating circuit. As a result, the resonant circuit thus constituted can avoid lowering of the Q factor, thereby realizing a high S/N ratio for the oscillating circuit IC.

Furthermore, by constituting the negative resistance generating integrated circuit 57 as described above, the collector ground capacitor and the emitter-ground capacitor normally connected between the oscillating transistor and the ground are not connected to the circuit board on which the negative resistance generating circuit is mounted. Instead, it is directly connected between the collector and emitter of the two oscillation transistors. Thus, a differential oscillation operation can be performed at a high frequency without using the ground pattern on the mounted circuit board, thereby providing a high-frequency oscillation circuit that is not affected by the ground pattern on the mounted circuit board as in the sixth embodiment. There are no characteristics such as a drop in the S/N ratio due to the influence of a potential difference generated in the pattern or even when external electromagnetic interference is generated.

As long as the negative resistance generating circuit 57, that is, the external negative resistance generating circuit is formed inside the integrated circuit, it is not limited to the structure in FIG. 13 .

Fig. 14 shows the structure of resonance circuits of seventh and eighth embodiments of the present invention. In this figure, 95 is a dielectric substrate; 7 is a resonator formed of strip lines on the dielectric substrate 95, which is half the length of the wavelength.

Reference numerals 9 and 24 are varactors (bare chips) in which anode terminals 90 and 91 of the varactor are formed on the front side of the chip and cathode terminals 92 and 93 of the varactor are formed on the back side of the chip. The cathode terminals 92 and 93 of the varactors of the two varactors 9 and 24 are connected via a cathode terminal connection pattern 94 (conductive pattern formed on a dielectric substrate 95 ). The dielectric substrate is preferably formed of a ceramic substrate or glass having a high Q factor and a high dielectric constant to provide excellent characteristics and a small size.

FIG. 15 shows the configuration of an example of an oscillation circuit using the resonance circuits of the seventh and eighth embodiments of the present invention. In this figure, 57 is a negative resistance generating integrated circuit; 15 and 16 are high-frequency output terminals; 33 is a tuning voltage power supply terminal; 34 is a bias voltage power supply terminal; 54 and 86 are ground terminals; 81 to 85 are resonant circuit terminals 98 is a resonant circuit module; 7 is a resonator; 9 and 24 are varactor diodes; 90 and 91 are anode terminals of varactor diodes; 94 is a cathode terminal connection pattern; 100 is a welding wire; 96 is an IC package.

Connection points 81 to 85 of the resonant circuit in FIG. 15 form bonding pads on the IC, have the same reference numerals as in FIGS. 12 and 13 (which are circuit diagrams representing seventh and eighth embodiments), and are connected to The resonant circuit module 98 thus matches the circuit diagrams shown in FIGS. 12 and 13 .

In addition, as shown in the figure, a resonance circuit module 98 and a negative resistance generating integrated circuit 57 are mounted in an IC package. In this case, however, the resonant circuit portion may also be formed as a resonant circuit module 98 disposed on the dielectric substrate shown in FIG. 14 and connected to the negative resistance generating integrated circuit 57 (ie, an external circuit) to constitute an oscillating circuit.

The above structure can realize the resonant circuit as a small resonant circuit module having a high Q factor, which is mounted in an IC package having a negative resistance generating circuit portion constituting the IC to provide a resonant circuit having a high overall S/N ratio. small oscillating circuit.

Furthermore, FIG. 16 shows the structure of another example of an oscillation circuit using the resonance circuits of the seventh and eighth embodiments of the present invention. In this figure, 57 is a negative resistance generating integrated circuit; 15 and 16 are high-frequency output terminals; 33 is a tuning voltage power supply terminal; 34 is a bias voltage power supply terminal; 54 and 86 are ground terminals; 81 to 85 are resonant circuit terminals Connection point; 7 is a resonator; 9 and 24 are varactor diodes; 90 and 91 are anode terminals of varactor diodes; 94 is a cathode terminal connection pattern; 100 is a welding wire; 97 is a dielectric substrate; 99 is a terminal electrode.

In FIG. 16, a dielectric substrate 97 includes terminal electrodes 99 whose side and upper surfaces are plated with gold and have bondable lands.

In addition, the resonator is half the wavelength long and its open junctions form a strip-shaped linear resonator on a dielectric substrate 97, and the cathode terminal connection pattern 94 of the varactor diode is also formed by a conductive pattern on the dielectric substrate 97.

For example, the varactor diodes 9 and 24 are mounted on the cathode terminal connection pattern 94 through an exposed chip. The negative resistance generating integrated circuit 57 is mounted on a dielectric substrate 97 .

Connection points 81 to 85 of the resonant circuit shown in FIG. 16 form bonding pads on the IC, have the same reference numerals as those shown in FIGS. The line 100 is connected to the resonator 7 and the anodes 90 and 91 of the varactor diodes to match the circuit diagrams shown in Figs. 12 and 13, thereby constituting an oscillating circuit.

Further, the high frequency output terminals 15 and 16, the tuning voltage power supply terminal 33, the bias voltage power supply terminal 34 and the ground terminals 54 and 86 are connected to terminal electrodes 99 formed on a dielectric substrate 97 as shown.

In this case, it is preferable to cover the dielectric substrate, the negative resistance generating integrated circuit chip mounted on the dielectric substrate, and the varactor diode chip with a sealant in order to protect the components.

The above structure can realize the resonant circuit as a resonant circuit module with a high Q factor, and then the negative resistance generating circuit chip constituting the IC can be mounted on the dielectric substrate constituting the resonant circuit, thereby providing a resonant circuit with a high total S/N Than the small oscillator circuit.

As described above, while the conventional technique constitutes an IC with an oscillating circuit together with a resonant circuit portion for the oscillating circuit, the present invention integrates a resonator, a variable capacitance diode, a capacitor, and a choke coil constituting a resonant circuit portion to form an IC. A module separate from the negative resistance generating circuit that constitutes an IC and includes an oscillation transistor. Thus, for example, forming a resonator from strip conductors on a dielectric substrate to provide a high Q factor, unlike IC processes, using conventional single discrete components for varactors can also increase Q factor and volume ratio, thereby realizing a resonant circuit with a high Q factor. Thus, an oscillation circuit IC having a high S/N ratio can be provided in combination with the oscillation circuit IC.

In the fifth to eighth embodiments, the resonant circuit is constituted as shown in FIGS. 1 and 2 or FIGS. 4 and 5, as long as the circuit includes a resonator and two varactor diodes, there is no limit to the included components such as capacitors and coils. and other components. In this case, elements not included in the resonance circuit may be included in the negative resistance generating circuit.

Although the first embodiment directly connects the bases and emitters of two oscillating transistors via a capacitor, the present invention is not limited in this respect, and the bases of these two transistors may be directly connected via a capacitor as shown in FIG. , or connect only the emitters of the two transistors directly via a capacitor as shown in FIG. 18 . In FIG. 3, only the collectors of the transistors are directly connected via a capacitor, or only the emitters of the transistors are directly connected via a capacitor. In this case, the base and collector can be connected directly without a capacitor.

Claims (10)

1. A high-frequency oscillating circuit comprising first and second oscillating transistors, characterized in that the bases of the first and second transistors are connected directly or via a capacitor whose impedance is lower than a predetermined value at the oscillating frequency, A differential signal output is obtained from the emitters of the first and second oscillating transistors as an oscillating output, and the high-frequency oscillating circuit also includes two varactor diodes, and the two varactor diodes are relatively high-frequency oscillating circuit The tuning voltage power supply terminal is symmetrically connected and connected in parallel with the resonator of the high frequency oscillating circuit. 2. A high-frequency oscillating circuit comprising first and second oscillating transistors, characterized in that the collectors of the first and second transistors are connected directly or via a capacitor whose impedance is lower than a predetermined value at the oscillating frequency, A differential signal output is obtained from between emitters of the first and second oscillating transistors as an oscillating output, and the high frequency oscillating circuit is a Clapp oscillator or a Colpitts oscillator. 3. A high-frequency oscillating circuit comprising first and second oscillating transistors, characterized in that the emitters of the first and second transistors are connected directly or via a capacitor whose impedance is lower than a predetermined value at the oscillating frequency, A differential signal output is obtained from between emitters of the first and second oscillating transistors as an oscillating output, and the high frequency oscillating circuit is a Clapp oscillator or a Colpitts oscillator. 4. A high frequency oscillating circuit comprising a first oscillating transistor; a first capacitor connected between the collector and the emitter of the first oscillating transistor; a second transistor; connected between the collector and the emitter of the second oscillating transistor The second capacitor between; the third capacitor, one end of which is connected to the collector of the first oscillating transistor; the fourth capacitor, one end of which is connected to the collector of the second oscillating transistor; A resonator between three capacitors and the other end of said fourth capacitor; a fifth capacitor connected between emitters of said first and second crystal oscillation transistors; a sixth capacitor, one end of which is connected to said The emitter of the first oscillating transistor; the seventh capacitor, one end of which is connected to the emitter of the second oscillating transistor, characterized in that the bases of the first and second oscillating transistors are directly or via their impedances at the oscillating frequency The eighth capacitor lower than a predetermined value is connected, and the oscillation output is obtained via the sixth and seventh capacitors. 5. A high-frequency oscillating circuit, comprising a first oscillating transistor; a first capacitor connected between the base and the emitter of the first oscillating transistor; a second transistor; connected between the base and the emitter of the second oscillating transistor The second capacitor between; the third capacitor, one end of which is connected to the base of the first oscillating transistor; the fourth capacitor, one end of which is connected to the base of the second oscillating transistor; A resonator between three capacitors and the other end of said fourth capacitor; a fifth capacitor connected between emitters of said first and second crystal oscillation transistors; a sixth capacitor, one end of which is connected to said The emitter of the first oscillating transistor; the seventh capacitor, one end of which is connected to the emitter of the second oscillating transistor, characterized in that the collectors of the first and second oscillating transistors are directly or via their impedances at the oscillating frequency The eighth capacitor lower than the predetermined value is connected, and the oscillation output is obtained through the sixth and seventh capacitors. The high-frequency oscillation circuit also includes two varactor diodes, and the two varactor diodes are relatively The tuning voltage power supply terminal of the high frequency oscillating circuit is symmetrically connected and connected in parallel with the resonator of the high frequency oscillating circuit. 6. The high-frequency oscillation circuit as claimed in claim 1, comprising a first buffer amplifier transistor, whose base is connected to the output from the emitter of said first oscillation transistor; a second buffer amplifier transistor, whose base connected to the output from the emitter of said second oscillating transistor, characterized in that the emitters of the first and second buffer transistors are connected directly or via a capacitor whose impedance is lower than a predetermined value at the oscillating frequency, after amplification, A differential signal output is obtained as an oscillating output from between the collectors of the first and second buffer transistors. 7. The high-frequency oscillation circuit as claimed in claim 2, comprising a first buffer amplifier transistor, whose base is connected to the output from the emitter of said first oscillation transistor; a second buffer amplifier transistor, whose base connected to the output from the emitter of said second oscillating transistor, characterized in that the emitters of the first and second buffer transistors are connected directly or via a capacitor whose impedance is lower than a predetermined value at the oscillating frequency, after amplification, A differential signal output is obtained as an oscillating output from between the collectors of the first and second buffer transistors. 8. The high-frequency oscillation circuit according to any one of claims 1 to 7, wherein the predetermined value of the impedance of the capacitor is a value at which oscillation can be generated. 9. The high-frequency oscillation circuit as claimed in claim 6, characterized in that a first inductor connected between the collector of the first oscillation transistor and the emitter of the first buffer amplifier transistor; The second inductor between the collector of the second oscillation transistor and the emitter of the second buffer amplifier transistor is characterized in that the same current path is used for the emitter current from the first buffer amplifier transistor and the emitter current from the second buffer amplifier transistor. For the collector current of the first oscillating transistor, the same current path is used for the emitter current from the second buffer amplifier transistor and the collector current from the second oscillating transistor. 10. The high-frequency oscillation circuit as claimed in claim 7, wherein the collector of the first oscillation transistor is connected to the emitter of the first buffer amplifier transistor, and the collector of the second oscillation transistor is connected to For the emitter of the second buffer amplifier transistor, the same current path is used for the emitter current from the first buffer amplifier transistor and the collector current from the first oscillation transistor, and the same current path is used for the collector current from the first buffer amplifier transistor. The emitter current of the second buffer amplifier transistor and the collector current from the second oscillation transistor.

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